package com.itheima.reggie.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.reggie.common.BaseContext;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否已完成登陆
 * filterName：过滤器的名字
 * urlPatterns：过滤的路径
 */
@Slf4j
@WebFilter(filterName = "LoginCheckFilter" , urlPatterns = "/*")
public class LoginCheckFilter implements Filter {
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain)
            throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse)servletResponse;

        //1.获取本次请求的URL
        String requestURI = request.getRequestURI();

        //定义一些不需要过滤的请求
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**",
                "/common/**",
                "/user/sendMsg",
                "/user/login"
        };

        //2.判断本次请求是否需要处理
        boolean check = check(urls, requestURI);

        //3.如果不需要处理，直接放行
        if (check) {
            filterChain.doFilter(request,response);
            return;
        }

        //4.1判断登陆状态，如果已登陆，直接放行
        if (request.getSession().getAttribute("employee") != null){
            //将当前登录的用户id设置到线程中
            Long empId = (Long)request.getSession().getAttribute("employee");
            BaseContext.setCurrentId(empId);

            filterChain.doFilter(request,response);
            return;
        }

        //4.2判断移动端用户的登陆状态，如果已登陆，直接放行
        if (request.getSession().getAttribute("user") != null){
            //将当前登录的用户id设置到线程中
            Long userId = (Long)request.getSession().getAttribute("user");
            BaseContext.setCurrentId(userId);

            filterChain.doFilter(request,response);
            return;
        }

        //5.如果未登录则返回未登录的结果，通过输出流方式向客户端页响应数据
        response.getWriter().write(JSON.toJSONString(R.error("NOTLOGIN")));
    }

    //路径匹配，检查本次是否需要放行
    public boolean check(String[] urls ,String requestURL){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURL);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
